If I'm not mistaken, you only convert RAW to TIFF only if you want to reduce the RAW file size without losing RAW data.

I shoot as a hobby but haven't picked up my camera lately.
I've used Topaz Denoise in the past but always use the default settings.
IIRC, there are profiles set for you. So you just need to click the profile that suits the image file, ISO or the way you want it to look.

For example, your photo may be shot on RAW with ISO 1600 using a crop frame.
ISO 1600 on crop frame will be quite noisy, so I will click RAW - Medium noise.

If I shoot RAW with ISO 1600 on a full frame, noise will be relatively low.
In this case, I will click RAW - Low noise.

There's a RAW - Very High (with debanding) option too meant for ISO12800 but it will make the photo look like a pastel painting.

The best way to make full use of it is to selectively apply the filter to selected parts of the image (i.e. background).
So you need to unapply the filter to several parts of the image you want to preserve (e.g. eyelids).

Despite all these noise reduction tools, some say that the best noise reduction software is in Photoshop itself.
I've tried some tutorials and the photos definitely has more details and lesser noise compared to the filters.
However, you need to tweak and experiment with every photo rather than bulk apply the filters.